JP7687863B2 - Dynamic damper and vehicle seat - Google Patents

Description

The present invention relates to a dynamic damper and a vehicle seat.

Patent Document 1 describes a vehicle seat equipped with a dynamic damper. The dynamic damper described in Patent Document 1 is fixed to a frame inside the seat back, and has a bracket having a top plate and a pair of side plates bent from both ends of the top plate to face each other, and a mass metal (weight) connected to the pair of side plates with a rubber elastic body and positioned to face the top plate.

The dynamic damper described in Patent Document 1 is fixed to the frame and positioned inside the seat back with the top plate of the bracket facing forward and a pair of side plates facing up and down when the seat back is in the normal upright position.

JP 2007-263181 A

2. Description of the Related Art Vehicle seats installed in automobiles include those that can be arranged in a variety of ways, with the seat back being able to be tilted forward and rotated to a horizontal position to form a table.
Such forward tilting of the seat back is often performed by the occupant with great force, and when the seat back reaches a predetermined horizontal position, the locking mechanism is activated and the rotation is suddenly stopped. Therefore, in the dynamic damper described in Patent Document 1, the weight collides with the top plate of the bracket with great force due to inertia, and it is likely to generate an unnecessary collision noise. This is also true when the seat back is tilted backward and rotated to make it into a simple bed, as the weight collides with the frame and a similar unnecessary collision noise may be generated.
Therefore, there is a demand for a dynamic damper and a vehicle seat that do not generate unnecessary collision noises when the seat back is rotated in response to seat arrangement.

In order to solve the above problems, the present invention has the following configuration.
1) A bracket having a metal plate-shaped base portion and a first opposing wall portion and a second opposing wall portion bent from both ends of the base portion in a first direction so as to face each other;
a damper body including a weight, a weight covering portion covering the weight, a first support which is a connecting column that elastically connects the weight covering portion and the first opposing wall portion, a second support which is a connecting column that elastically connects the weight covering portion and the second opposing wall portion, and a third support which is a connecting column that elastically connects the weight covering portion and the base portion;
Equipped with
The weight is a dynamic damper supported on the bracket by a first support, a second support, and a third support.
2) The dynamic damper according to 1), wherein any one of the first support, the second support, and the third support is constituted by a plurality of the connecting columns.
3) A seat cushion, a seat back having a seat back frame and the dynamic damper according to 1) or 2) attached to the seat back frame,
The dynamic damper is a vehicle seat in which the first direction is a longitudinal direction of the seat back frame and the base portion is attached in a position facing the front side of the seat back frame.

According to one aspect of the present invention, the effect is that unnecessary hitting sounds are not generated when the seat back is rotated in response to seat arrangement.

FIG. 1 is a perspective view of a seat ST, which is an example of a vehicle seat according to an embodiment of the present invention, as viewed obliquely from above and on the front left. FIG. 2 is a rear view of the dynamic damper 91 provided in the seat ST. FIG. 3 is a left side view of the dynamic damper 91. FIG. FIG. 4 is a graph showing the relationship between the frequency of the dynamic damper 91 and the resonance magnification in the left-right direction. FIG. 5 is a graph showing the relationship between the frequency of the dynamic damper 91 and the resonance magnification in the vertical direction. FIG. 6 is a rear view of the dynamic damper 91A of the first modified example. FIG. 7 is a left side view of the dynamic damper 91A. FIG. 8 is a rear view of a dynamic damper 91B according to the second modification. FIG. 9 is a left side view of the dynamic damper 91B. FIG. 10 is a rear view of a dynamic damper 91C according to the third modified example. FIG. 11 is a left side view of the dynamic damper 91C.

A vehicle seat according to an embodiment of the present invention will be described with reference to FIG. 1 using seat ST as an example. For ease of explanation, the up, down, left, right, front and rear directions are defined as directions indicated by arrows in FIG. 1. FIG. 1 is a perspective view of seat ST as seen from diagonally above and to the left front.

The seat ST is a vehicle seat to be installed in a vehicle such as an automobile, and has a seat cushion ST1 and a seat back ST2 as shown in FIG.
The seat cushion ST1 is supported by a pair of rails 92, 92 that extend in the front-rear direction on a floor 93 of the vehicle and are laid parallel to each other and spaced apart in the left-right direction.

The seat back ST2 is connected to the rear end of the seat cushion ST1 in a reclining structure that allows it to be tilted backward and locked at any angle. In addition, the seat back ST2 can be arranged to be tilted forward as shown by the arrow DR1 in Figure 1, so that the rear surface is in a table-like position that is nearly horizontal.

The seat back ST2 contains a frame-shaped seat back frame ST2a that serves as the framework, and a dynamic damper 91 that is fixed to the seat back frame ST2a. The dynamic damper 91 is located in the seat back ST2 at approximately the center in the width direction and slightly above the center in the up-down direction.

The dynamic damper 91 will be described with reference to Figures 2 and 3. Figure 2 is a rear view of the dynamic damper 91 alone, and Figure 3 is a left side view of the dynamic damper 91 attached to the seat back frame ST2a.

The dynamic damper 91 has a bracket 1 and a damper body 2 .
The bracket 1 is formed by press-molding a metal plate, and has a base portion 11, an upper opposing wall portion 12, an upper mounting portion 13, a lower opposing wall portion 14, and a lower mounting portion 15. The metal plate is, for example, SPCC (cold rolled steel plate).
The bracket 1 is formed symmetrically with respect to a center line CL1 that extends in the up-down direction.

The base portion 11 is a flat rectangular portion whose longer side is in the up-down direction, which is a first direction, when viewed from behind.
The upper facing wall portion 12 is a flat plate-like portion bent 90° rearward from the upper end of the base portion 11. The upper mounting portion 13 is a flat plate-like portion bent 90° upward from the rear end of the upper facing wall portion 12.
The lower opposing wall portion 14 is a flat plate-like portion bent 90° rearward from the lower end of the base portion 11 and opposed in parallel to the upper opposing wall portion 12. The lower mounting portion 15 is a flat plate-like portion bent 90° downward from the rear end of the lower opposing wall portion 14.
That is, the upper opposing wall portion 12 and the lower opposing wall portion 14 are a first opposing wall portion and a second opposing wall portion bent from both ends of the base portion 11 in the first direction so as to face each other.

An upper protrusion 131 that protrudes upward is formed in the left-right center of the upper attachment portion 13. A through hole 132 is formed in the upper protrusion 131 on the center line CL1.
A lower protruding portion 151 that protrudes downward is formed in the left-right central portion of the lower mounting portion 15. A through hole 152 is formed in the lower protruding portion 151 on the center line CL1.

The damper body 2 has a rectangular parallelepiped weight 21, which is a metal block, and a rubber covering 22 that covers the entire surface of the weight 21. The metal that forms the weight 21 is, for example, SS400, a rolled steel material for general construction. The rubber that forms the covering 22 is, for example, NR/SBR (a blend of natural rubber and styrene butadiene rubber).

The covering portion 22 has a weight covering portion 221 that covers the weight 21 , and a first connecting post 222 , a second connecting post 223 , a third connecting post 225 , a fourth connecting post 226 , and a fifth connecting post 228 .
The weight covering portion 221 has an upper surface 2t, a lower surface 2d, a left side surface 2l, a right side surface 2r, a front surface 2f, and a rear surface 2k.
The first connecting post 222 and the second connecting post 223 are cylindrical and are provided on the upper surface 2t of the weight covering portion 221 so as to extend upward and be spaced apart from each other on the left and right sides.
The upper ends of the first connecting post 222 and the second connecting post 223 are connected to a thin plate-shaped upper base 224 , which is fixed to the upper opposing wall portion 12 of the bracket 1 .
The third connecting post 225 and the fourth connecting post 226 are cylindrical and are formed on the lower surface 2d of the weight covering portion 221 so as to extend downward and be spaced apart from each other on the left and right sides.
The lower ends of the third connecting post 225 and the fourth connecting post 226 are connected to a thin plate-shaped lower base 227 , which is fixed to the lower opposing wall portion 14 of the bracket 1 .

The fifth connecting post 228 is formed in a cylindrical shape extending forward from the front surface 2f of the weight covering portion 221 at the same position as the center of gravity G of the weight 21 when viewed from behind.
The front end of the fifth connecting post 228 is connected to a thin plate-shaped front pedestal 229 , which is fixed to the base portion 11 of the bracket 1 .

As shown in Figures 2 and 3, if the first connecting column 222, the second connecting column 223, the third connecting column 225, the fourth connecting column 226, and the fifth connecting column 228 are respectively defined as the first support part PL1 to the fifth support part PL5, the weight 21 and the weight covering part 221 are elastically supported with respect to the bracket 1 by the first support part PL1 to the fifth support part PL5.
The first support portion PL1 and the second support portion PL2 connecting the weight covering portion 221 and the upper opposing wall portion 12 constitute the first support portion P1. The third support portion PL3 and the fourth support portion PL5 connecting the weight covering portion 221 and the lower opposing wall portion 14 constitute the second support portion P2. The fifth support portion PL5 connecting the weight covering portion 221 and the base portion 11 constitutes the third support portion P3.

The upper protrusion 131 and the lower protrusion 151 of the bracket 1 are fixed to the mounting frame ST2b and the mounting frame ST2c of the seat back frame ST2a of the seat back ST2 using fasteners N1 and N2 such as bolts and nuts, respectively. As a result, the dynamic damper 91 is housed and arranged in the seat back ST2. In detail, the dynamic damper 91 is arranged in a position in which the vertical direction is the longitudinal direction of the seat back ST2 and the base part 11 is on the front side (backrest side).

During the seat arrangement of the seat ST, the dynamic damper 91 attached to the seat back frame ST2a is subjected to inertial forces corresponding to the forward and backward tilting of the seat back ST2, as well as inertial forces generated according to the behavior of the vehicle. The mass of the weight 21 of the dynamic damper 91, as well as the shapes and elastic coefficients of the first support part PL1 to the fifth support part PL5, are set so that the movement caused by the inertial forces is suppressed at a preset response acceleration.

When an inertial force acts on the weight 21 in the vertical direction, one of the first support portion PL1 and the second support portion PL2 and the third support portion PL3 and the fourth support portion PL4 is compressed in the axial direction and the other is expanded in the axial direction. Furthermore, the fifth support portion PL5 is shear-deformed in the direction perpendicular to the axis.
As a result, the upward movement of the weight 21 is appropriately suppressed with a preset response characteristic.

When a lateral inertial force acts on the weight 21, the first support portion PL1 to the fifth support portion PL5 are shear-deformed in a direction perpendicular to each axis.
As a result, the left-right movement of the weight 21 is appropriately suppressed by the elastic repulsive forces of the first support portion PL1 to the fifth support portion PL5 with preset response characteristics.

When a forward or backward inertial force acts on the weight 21, the first support part PL1 to the fourth support part PL4 are shear deformed in a direction perpendicular to each axis, and the fifth support part PL5 is compressed or expanded in the axial direction. Therefore, the forward and backward movement of the weight 21 is appropriately suppressed by a preset response characteristic.

In this way, in the dynamic damper 91, the damper body 2 and the base portion 11 of the bracket 1 are connected by the fifth support portion PL5 extending in the front-rear direction. Therefore, even if the seat back ST2 is rotated forward by the seat arrangement, the weight 21 and the weight covering portion 221 do not collide with the base portion 11 of the bracket 1. In addition, even if the seat back ST2 is rotated backward, the weight 21 and the weight covering portion 221 do not collide with the seat back frame ST2a of the seat back ST2, etc.
As a result, the dynamic damper 91 does not generate unnecessary collision noises when the seat back ST2 rotates in accordance with seat arrangement.

Next, the relationship between frequency and resonance magnification of the dynamic damper 91 will be described with reference to Figures 4 and 5. Figure 4 is a graph showing the relationship between the frequency of the dynamic damper 91 and the resonance magnification in the left-right direction. Figure 5 is a graph showing the relationship between the frequency of the dynamic damper 91 and the resonance magnification in the up-down direction. In both graphs, the characteristics of a conventional dynamic damper that does not have the fifth connecting pillar 228 are shown by dashed lines.

4, in the left-right direction, the dynamic damper 91 exhibits a peak around 19 Hz that is suppressed to about 7 times the resonance magnification (about 9 times) of the conventional dynamic damper around 18 Hz. Also, the dynamic damper 91 exhibits a small resonance at 29 to 30 Hz with a resonance magnification of just over 2 times that of the conventional dynamic damper, which is not observed in the conventional dynamic damper.
As shown in FIG. 5, in the vertical direction, which is the longitudinal direction, in the dynamic damper 91, instead of the small peak observed near 19 Hz in the conventional dynamic damper, peaks with a resonance magnification of approximately 8 times appear at two locations, near 19 Hz and near 28 Hz.

Thus, even if the fifth connecting pillar, which is the fifth support part PL5, is included, the characteristic is the same as when the fifth support part PL5 is not included, in that a peak occurs around 19 Hz, and it can be said to function as a dynamic damper 91. The dynamic damper 91 can suppress resonance of the seat ST by optimizing the resonance magnification by adjusting the shapes of the first support part PL1 to the fifth support part PL5 and the mass of the weight 21, etc.

The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.

(Variation 1)
A dynamic damper 91A which is a first modified example of the dynamic damper 91 will be described with reference to FIGS.
FIG. 6 is a rear view of the dynamic damper 91A of the first modified example, and FIG. 7 is a left side view of the dynamic damper 91A.

The dynamic damper 91A has a damper body 2A instead of the damper body 2 of the dynamic damper 91. The damper body 2A has a covering portion 22A that covers the entire surface of the weight 21.
The covering portion 22A has a weight covering portion 221A having a first protruding portion 231, a second protruding portion 232, a third protruding portion 233, and a fourth protruding portion 234, instead of the weight covering portion 221. The weight covering portion 221A has an upper surface 2At, a lower surface 2Ad, a left side surface 2Al, a right side surface 2Ar, a front surface 2Af, and a rear surface 2Ak.

The first protrusion 231 is formed on an upper portion of the rear surface 2Ak of the weight covering portion 221A. The first protrusion 231 is a protrusion that has a constant shape, a generally triangular mountain shape, in cross section and extends in the left-right direction.
The third protrusion 233 is formed on the front surface 2Af of the weight covering portion 221A so as to protrude forward at the same vertical position as the first protrusion 231 and with the same shape.
The second protruding portion 232 and the fourth protruding portion 234 have the same shape as the first protruding portion 231 and the third protruding portion 233 and are formed to be vertically symmetrical on the weight covering portion 221A.

The dynamic damper 91A has a damper body 2A on which first to fourth protrusions 231 to 234 are formed. As a result, when an excessive rotational force acts around the center of gravity G as indicated by the arrow DR2 as shown in Fig. 7, for example, one of the thick third protrusion 233 and the fourth protrusion 234, which is not a thin portion, collides with the base portion 11 of the bracket 1.
Since the third protrusion 233 and the fourth protrusion 234 are portions in which the rubber is formed thickly, even if the damper main body 2A collides with the bracket 1 due to an unexpected excessive rotational force, the generated sound volume is suppressed.

(Variation 2)
A dynamic damper 91B which is a second modified example of the dynamic damper 91 will be described with reference to FIGS.
FIG. 8 is a rear view of a dynamic damper 91B according to the second modified example, and FIG. 9 is a left side view of the dynamic damper 91B.

The dynamic damper 91B has a damper body 2B instead of the damper body 2 of the dynamic damper 91.
The damper body 2B uses a weight 21B, which has a shape in rear view formed by connecting a rectangle to the lower part of a trapezoid with a narrow upper part, instead of the weight 21 of the damper body 2. The damper body 2B has a rubber covering portion 22B that covers the entire surface of the weight 21B.
The covering portion 22B has a weight covering portion 221B that covers the weight 21B, and a first connecting post 222, a second connecting post 223, a third connecting post 225, a fourth connecting post 226, and a fifth connecting post 228.

The weight covering part 221B has an upper surface 2Bt, a lower surface 2Bd, a front surface 2Bf, and a rear surface 2Bk. The weight covering part 221B also has a left inclined side surface 2Blg and a right inclined side surface 2Brg, which respectively approach the center line CL1 as the left side surface and the right side surface, and a left side surface 2Bl and a right side surface 2Br, which are connected to the lower sides of the left inclined side surface 2Blg and the right inclined side surface 2Brg, respectively, and are parallel to the center line CL1.
Due to this shape, the position of the center of gravity GB of the damper body 2B is lower than the position of the center of gravity G of the damper body 2.
The fifth connecting post 228, which is the fifth support part PL5, is provided on the front surface 2Bf of the damper main body 2B at a position corresponding to the center of gravity GB below the damper main body 2.

Although the shape of the weight 21B of the dynamic damper 91B is different from that of the weight 21 of the dynamic damper 91, like the dynamic damper 91, no unnecessary hitting noise is generated when the seat back ST2 rotates in response to seat arrangement.

(Variation 3)
A dynamic damper 91C which is a third modified example of the dynamic damper 91 will be described with reference to FIGS.
FIG. 9 is a rear view of a dynamic damper 91C of the third modified example, and FIG. 10 is a left side view of the dynamic damper 91C.

The dynamic damper 91C has a damper body 2C instead of the damper body 2B of the dynamic damper 91B. The damper body 2C has a covering portion 22C that covers the entire surface of the weight 21B. The covering portion 22C has a weight covering portion 221C that covers the entire surface of the weight 21B. The weight covering portion 221C has an upper surface 2Ct, a lower surface 2Cd, a front surface 2Cf, and a rear surface 2Ck. The weight covering portion 221C also has a left inclined side surface 2Clg and a right inclined side surface 2Crg that approach the center line CL1 as the left and right sides, respectively, and a left side surface 2Cl and a right side surface 2Cr that are connected to the lower sides of the left inclined side surface 2Clg and the right inclined side surface 2Crg, respectively, and are parallel to the center line CL1.

The dynamic damper 91C differs from the dynamic damper 91B of variant example 2 in that the fifth support part PL5 is not a single fifth connecting column 228 but a fifth connecting column group 251G, which is a group of multiple (three in this example) connecting columns 251-253.
Specifically, the fifth connecting column group 251G, which is the fifth support part PL5, includes a connecting column 251 provided above at the same position as the center of gravity GC in the left-right direction, and connecting columns 252 and 253 provided below the center of gravity GC on the right and left sides, respectively, in the left-right direction. Flat plate-shaped pedestals 251a to 253a are provided at the tips of the connecting columns 251 to 253. The pedestals 251a to 253a are fixed to the base part 11.

Like the dynamic damper 91B of variant 2, the dynamic damper 91C does not generate unnecessary hitting noises when the seat back ST2 rotates in response to seat arrangement.

The first support body P1 is not limited to being composed of two connecting pillars, the first connecting pillar 222 and the second connecting pillar 223. The first support body P1 may be composed of only one of the connecting pillars or three or more connecting pillars.
The second support body P2 is not limited to being composed of two connecting pillars, that is, the third connecting pillar 225 and the fourth connecting pillar 226. The second support body P2 may be composed of only one of the connecting pillars or three or more connecting pillars.

The vehicle is not limited to an automobile. The shapes of the first to fifth support parts PL1 to PL5 are not limited to cylindrical as long as they are columnar. In addition, the upper base 224, the lower base 227, the front base 229, and the bases 251a to 253a do not have to be provided.

1 Bracket 11 Base part 12 Upper opposing wall part 13 Upper mounting part 131 Upper protruding part 132 Through hole 14 Lower opposing wall part 15 Lower mounting part 151 Lower protruding part 152 Through hole 2, 2A, 2B, 2C Damper main body 2f, 2Af, 2Bf, 2Cf Front 2k, 2Ak, 2Bk, 2Ck Rear surface 2t, 2At, 2Bt, 2Ct Top surface 2d, 2Ad, 2Bd, 2Cd Bottom surface 2l, 2Al, 2Bl, 2Cl Left side 2Blg, 2Clg Left inclined side 2r, 2Ar, 2Br, 2Cr Right side 2Brg, 2Crg Right inclined side 21, 21B Weight 22, 22A, 22B, 22C Covering part 221, 221A, 221B, 221C Weight covering portion 222 First connecting column 223 Second connecting column 224 Upper base 225 Third connecting column 226 Fourth connecting column 227 Lower base 228 Fifth connecting column 229 Front base 231 First protrusion 232 Second protrusion 233 Third protrusion 234 Fourth protrusion 251G Fifth connecting column group 251, 252, 253 Connecting columns 251a, 252a, 253a Base 91, 91A, 91B, 91C Dynamic damper 92 Rail 93 Floor CL1 Center line N1, N2 Fixing device G, GB Center of gravity P1 to P3 First to third supports PL1 to PL5 First to fifth support portions ST Seat (vehicle seat)
ST1 Seat cushion ST2 Seat back ST2a Seat back frame ST2b, ST2c Mounting frame

Claims (3)

a bracket having a metal plate-shaped base portion and a first opposing wall portion and a second opposing wall portion bent from both ends of the base portion in a first direction so as to face each other;
a damper body including a weight, a weight covering portion covering the weight, a first support which is a connecting column that elastically connects the weight covering portion and the first opposing wall portion, a second support which is a connecting column that elastically connects the weight covering portion and the second opposing wall portion, and a third support which is a connecting column that elastically connects the weight covering portion and the base portion;
Equipped with
The weight is a dynamic damper supported on the bracket by a first support, a second support, and a third support. The dynamic damper according to claim 1, wherein any one of the first support, the second support, and the third support is composed of a plurality of the connecting columns. A seat cushion, a seat back having a seat back frame and the dynamic damper according to claim 1 or 2 attached to the seat back frame,
The dynamic damper is attached in a position in which the first direction is a longitudinal direction of the seat back frame and the base portion faces the front side of the seat back frame.

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